"""
Provides the :class:`~martini.sources.colibre_source.ColibreSource` class.
Facilitates working with Colibre simulations as input.
"""
from scipy.spatial.transform import Rotation
from typing import TYPE_CHECKING
from astropy import units as U
from astropy.coordinates import ICRS
from .swiftgalaxy_source import SWIFTGalaxySource
from ..L_coords import L_coords
if TYPE_CHECKING:
from swiftgalaxy import SWIFTGalaxy
from astropy.coordinates.builtin_frames.baseradec import BaseRADecFrame
[docs]
class ColibreSource(SWIFTGalaxySource):
"""
Class abstracting HI sources designed to work with Colibre simulations.
Uses the :mod:`swiftsimio` and :mod:`swiftgalaxy` modules.
Parameters
----------
galaxy : ~swiftgalaxy.reader.SWIFTGalaxy
Instance of a :class:`~swiftgalaxy.reader.SWIFTGalaxy`.
distance : ~astropy.units.Quantity
:class:`~astropy.units.Quantity`, with dimensions of length.
Source distance, also used to set the velocity offset via Hubble's law.
vpeculiar : ~astropy.units.Quantity, optional
:class:`~astropy.units.Quantity`, with dimensions of velocity.
Source peculiar velocity along the direction to the source centre.
rotation : ~scipy.spatial.transform.Rotation, optional
A rotation to apply to the source particles, specified using the
:class:`~scipy.spatial.transform.Rotation` class. That class supports many ways to
specify a rotation (Euler angle, rotation matrices, quaternions, etc.). Refer to
the :mod:`scipy` documentation for details. Note that the ``y-z`` plane will be
the one eventually placed in the plane of the "sky". Cannot be used at the same
time as ``L_coords``.
L_coords : ~martini.L_coords.L_coords, optional
A named tuple specifying 3 angles. Import it as ``from martini import L_coords``.
The angles are used to orient the galaxy relative to its angular momentum vector,
"L". The routine will first identify a preferred plane based on the angular
momenta of the central 1/3 of HI gas. This plane will then be rotated to lie in
the plane of the "sky" (``y-z`` plane), rotated by an angle ``az_rot`` around the
angular momentum vector (rotation around ``x``), then inclined by ``incl`` towards
or away from the line of sight (rotation around ``y``) and finally rotated on the
sky to set the position angle ``pa`` (second rotation around ``x``). All rotations
are extrinsic. The position angle refers to the receding side of the galaxy
measured East of North. The angles should be specified using syntax like:
``L_coords=L_coords(incl=0 * U.deg, pa=270 * U.deg, az_rot=0 * U.deg)``. These
example values are the defaults. Cannot be used at the same time as ``rotation``.
ra : ~astropy.units.Quantity, optional
:class:`~astropy.units.Quantity`, with dimensions of angle.
Right ascension for the source centroid.
dec : ~astropy.units.Quantity, optional
:class:`~astropy.units.Quantity`, with dimensions of angle.
Declination for the source centroid.
coordinate_frame : ~astropy.coordinates.builtin_frames.baseradec.BaseRADecFrame, \
optional
The coordinate frame assumed in converting particle coordinates to RA and Dec, and
for transforming coordinates and velocities to the data cube frame. The frame
needs to have a well-defined velocity as well as spatial origin. Recommended
frames are :class:`~astropy.coordinates.GCRS`, :class:`~astropy.coordinates.ICRS`,
:class:`~astropy.coordinates.HCRS`, :class:`~astropy.coordinates.LSRK`,
:class:`~astropy.coordinates.LSRD` or :class:`~astropy.coordinates.LSR`. The frame
should be passed initialized, e.g. ``ICRS()`` (not just ``ICRS``).
"""
def __init__(
self,
galaxy: "SWIFTGalaxy",
*,
distance: U.Quantity[U.Mpc],
vpeculiar: U.Quantity[U.km / U.s] = 0 * U.km / U.s,
rotation: Rotation | None = None,
L_coords: L_coords | None = None,
ra: U.Quantity[U.deg] = 0.0 * U.deg,
dec: U.Quantity[U.deg] = 0.0 * U.deg,
coordinate_frame: "BaseRADecFrame" = ICRS(),
) -> None:
# No special functionality wanted/needed:
super().__init__(
galaxy,
distance=distance,
vpeculiar=vpeculiar,
rotation=rotation,
L_coords=L_coords,
ra=ra,
dec=dec,
coordinate_frame=coordinate_frame,
_mHI_g=galaxy.gas.masses.to_astropy()
* galaxy.gas.element_mass_fractions.hydrogen.to_astropy()
* galaxy.gas.species_fractions.HI.to_astropy(),
)
return